Revert "README: add Go version note"

It was updated.

This reverts commit 9aa290b952725a3b260fd9004934b6c2a079b6b7.

Signed-off-by: Tianling Shen <[email protected]>

README.md

@@ -72,19 +72,6 @@
 
 ### Note
 
-- - -
-#### ⚠ For OpenWrt 21.02 or lower version
-You have to manually upgrade Golang toolchain to [1.18](https://github.com/openwrt/packages/tree/openwrt-22.03/lang/golang) or higher to compile Xray-core.
-
-e.g.:
-
-```bash
-./scripts/feeds update packages
-rm -rf feeds/packages/lang/golang
-svn co https://github.com/openwrt/packages/branches/openwrt-22.03/lang/golang feeds/packages/lang/golang
-```
-- - -
-
 If you want to use this repo with official OpenWrt source tree, the following packages need to be added manually:
 
 - [dns2socks](https://github.com/immortalwrt/packages/tree/master/net/dns2socks)